Thanks for the additional information!  I can now reproduce a hang using just Ctrl-5 on a US keyboard input method.  Ctrl-5 is the default IDLE keyboard accelerator for the "Tabify Region" menu item under the "Format" menu cascade for an edit window.  With any current Python (2.7.3, 3.2.3, or 3.3.0rc3) linked with Cocoa Tk 8.5, using the Ctrl-5 accelerator key causes the hang, requiring a force quit.  Selecting the menu item with a mouse causes the "Tab Width" window to appear as expected.  Ctrl-5 seems to work properly with Pythons linked with either Carbon Tk 8.4 or with X11 8.5.  There is a similar hang behavior with Ctrl-6 "Untabify Region" using Cocoa Tk 8.5 as well.  Attached is an excerpt from a hang dump when running with a debug framework build of 3.3 tip.